Android Example Valid EAN13 Barcode String

Public Sub BarcodeEAN13() As String
    
    Dim brcod As String = Rnd(100000000,214000000)
    brcod = "950" & brcod  '<<< change the beginning 3 digits according country, see: https://en.wikipedia.org/wiki/List_of_GS1_country_codes
    
    Dim x As Int = 0
    If brcod.Length=12 Then
        Dim odds,evens As List
        odds.Initialize
        evens.Initialize
        For i=0 To 11
            If i=0 Or i=2 Or i=4 Or i=6 Or i=8 Or i=10 Then odds.Add(brcod.CharAt(i))
            If i=1 Or i=3 Or i=5 Or i=7 Or i=9 Or i=11 Then evens.Add(brcod.CharAt(i))
        Next
        Dim od As Int = odds.Get(0) + odds.Get(1) +odds.Get(2) +odds.Get(3) +odds.Get(4) +odds.Get(5)
        Dim ev As Int = (evens.Get(0) + evens.Get(1) +evens.Get(2) +evens.Get(3) +evens.Get(4) +evens.Get(5)) * 3
        Dim tt As String = od + ev
        Dim ld As String = tt.SubString2(tt.Length-1,tt.Length)
        If ld=0 Then
            x = 0
        Else
            x = 10 - ld
        End If
    End If
    
    Return brcod & x
    
End Sub